Weight and mass gainers for skinny guys: Ultimate Guide (2025)

If you’re a naturally skinny guy struggling to gain weight, you’re not alone — and you’re in the right place. With the right mass gainer supplement, you can finally start building serious size and muscle without force-feeding or feeling overwhelmed.

At Muscle Products Store, we’ve been where you are. We’ve tested everything — from cheap gainers to the most premium formulas — and built this guide to help you pick the best weight gainer for your body type, metabolism, and goals.

🧠 What Is a Mass Gainer & How Does It Work?

A mass gainer (or weight gainer) is a high-calorie shake packed with protein, carbs, and healthy fats. It’s designed to help people with fast metabolisms — aka hardgainers — consume enough calories to build muscle and gain size.

Each serving typically contains:

• 500–1300+ calories

• 20–60g of protein

• Complex carbs & healthy fats

• Often added creatine, amino acids, and vitamins

👉 Ideal for:

• Skinny guys struggling to eat enough

• Hardgainers who burn calories too fast

• Anyone needing extra calories for bulking

🔍 How to Choose the Right Mass Gainer

✅ Fast Metabolism?

Go for high-calorie mass gainers like Mutant Mass Extreme or Critical Mass to fuel fast growth.

✅ Slower Metabolism?

Choose leaner formulas like USN Muscle Fuel Anabolic to gain muscle without excess fat.

✅ Can’t eat enough?

Weight gainer shakes are a life-saver. They help you hit your daily calorie goal without stuffing yourself at every meal.

🏆 Best Mass Gainers for Skinny Guys (Fast Metabolism)

1. Mutant Mass Extreme – Best Overall Mass Gainer

The ultimate choice for hardgainers.

✔ Huge calorie load per serving
✔ Premium protein blend + clean carbs
✔ Great with Mutant Creakong CX8 for even more growth

💥 Perfect for: Skinny guys needing serious size fast

2. Applied Nutrition Critical Mass Original

A high-calorie, budget-friendly mass gainer loaded with nutrients.

✔ Mixes easily
✔ Great taste
✔ Pairs well with Applied Nutrition Creatine for next-level performance

3. USN Hyperbolic Mass

Designed to pack on mass with added creatine for strength.

✔ Engineered for muscle volume
✔ Helps fuel intense gym sessions

💪 Best Weight Gainers for Skinny Guys (Slower Metabolism)

USN Muscle Fuel Anabolic – Best Lean Mass Gainer

Lower in calories but rich in nutrients — great for controlled gains.

✔ Perfect for lean bulking
✔ Works as a complete meal replacement
✔ Minimizes fat gain

⚖️ Fast vs. Controlled Weight Gain — Which Is Best?

Fast Mass Gain

Great if you’re super skinny and want size ASAP.

Recommended Products:
✔ Mutant Mass Extreme
✔ Serious Mass
✔ Critical Mass

💡 Pro Tip: Take your shake immediately after workouts to refuel and prevent muscle breakdown.

Lean, Controlled Muscle Gain

Ideal if you’re gaining easily or want a more aesthetic look.

Recommended Products:
✔ USN Muscle Fuel Anabolic
✔ Whey protein + creatine stack
✔ Amino acids for recovery without bulk

🔥 Our Top Mass Gainer Picks for Skinny Guys

All of these:
✔ Mix well
✔ Taste great
✔ Are trusted by real lifters (not just influencers)

💡 What to Look For in a Mass Gainer

📊 Calorie Density
Go for 500–1300+ calories depending on your metabolism and goal.

💪 Protein Content
At least 20–30g of protein per serving. Quality protein = more muscle.

🍚 Carbs & Fats
Look for complex carbs (oats, sweet potato) and healthy fats (MCTs, sunflower oil). Avoid gainers loaded with sugar.

🧪 Added Nutrients
Extra vitamins, minerals, and creatine are a bonus — they support recovery, energy, and overall results.

📈 How to Use Mass Gainers for Best Results

• Post-Workout: Rebuild muscle after training

• Between Meals: Boost total daily calories

• With Milk: Adds taste and calories

• Stay Consistent: Gains come from daily intake, not just a few shakes

Track your weight weekly and adjust as needed — your goal is to consistently gain 0.25–0.5kg per week.

🚀 Final Takeaway: What’s the Best Mass Gainer for Skinny Guys?

If you’re serious about building size, mass gainers are your shortcut to a bigger, stronger version of yourself.

Whether you want fast gains or controlled lean muscle, there’s a shake that fits your goal.

“I used to be the skinniest guy in the gym. Once I found the right mass gainer and stuck to the plan, I finally started growing. These products work — because I’ve used them.”

👉 Explore our full range of Mass Gainers for Skinny Guys and take the first step toward your transformation.